摘要 |
<p>A device to take and analyse a gas sample from a heat exchanger, esp. from the cyclone preheater of the waste gases from a rotary kiln, consists of an injector which extracts a gas side stream and returns it to the duct at a point upstream. A pump branches off a test sample of the gas for an analyser. A blower in an auxiliary gas pipe feeds the injector. Solenoid valves, controlled by a unit coupled to the manual setter of the injector and to a pressure gauge, shut the test gas and the return circuit when a set vacuum is exceeded. This requires only short sampling pipes which are not likely to be clogged by deposits. The valves make it possible to blow out any occasional deposits.</p> |